More about cycling....

[ClamKnuckle]

I have a 90 gal with 145 lbs LR and about a 3" DSB. Tomorrow I'll be receiving another 40 bs LR and 20 LS from liverocks.com

The LR Ialready have is fully cured and came from a tank that was running for years, the sand is new (that's why i got the LS to seed it)

I obviously have to cycle the tank but I want as little LR die off as possible. I read about the raw shrimp cycle, and have read posts about doing water changes to help keep the LR okay, even though it will prolong the cycle. I have also read in books that you can add food to the tank, a little each day, instead of the shrimp. Nothing was mentioned about water changes. Will the food idea work better on the LR? If not, then how often and how large of water changes should I do?

 

[steve-s]

With the 145 lbs of rock you already have, the additional rock should not really be much of a problem unless you have animals in the tank. The old rock should be able to process any die off the new rock might have. I would even be willing to bet you only see a marginal increase in NO2 and NO3 depending on what condition the rock arrives in. From what others have passed along about LR.com, I don't even think water changes will be needed but I would still be prepared.

If you do need to do water changes, about 20-25% depending on the NH3/NO2 levels. FWIW, when using uncured LR to cycle the tank, the amount of nutient is usually quite high and water changes will not really prolong the cycle that you'd notice. It's typically in new systems that are using well cured or no LR that it can prolong things due to insufficient nutrient/bacteria being available in the first place even when adding a fuel source.

Cheers
Steve